I saw this video and thought of this thread. Hope it contributes something!

"It does feel like something to be wrong; it feels like being right." -Kathryn Schulz
I am 100% certain that I am wrong about something I am certain about right now. Because even if everything I stand for turns out to be completely true, I was still wrong about being wrong.

Living for infinte time is theoretically impossible, as long as your body (from whatever material it is made of) contains any protons. Ay proton will statistically dissolve in 10^30 years. If your body contains x protons, then the probability that all of thoose protons dissolve in the same second, is 1(10^30)^x)^(1,8*10^10)= 1:10^54x*10^10 x sholud be about 3*10^30
In order to bear witness to such an event we would have to wait for faaaaaar longer than the unirverse is likely to live for. So in practice it doesn't mean much, but it's interesting i think...

..."we can be truly free - not because we can rebel against the the tyranny of the selfish replicators but because we know that there is no one to rebel."
Susan Blackmore : The Meme Machine

So what you're saying is that we can't live forever because our protons decay but the universe will go extinct before that - oh goody.
Still , cruising the darkness of space , after every star has died , gathering energy from strange an alien sources and living on sounds interesting ... granted the proton decay is something to factor in.

"So what you're saying is that we can't live forever because our protons decay but the universe will go extinct before that - oh goody.
"
That is exactly what I was saying that is why this proton thing doesn't have any importance, it's just interesting. Unless we somehow learn how to travel into another universe (if they exist). That way we could always go to another universe, before the current one become inhabitable.

..."we can be truly free - not because we can rebel against the the tyranny of the selfish replicators but because we know that there is no one to rebel."
Susan Blackmore : The Meme Machine

Will it actually "end" ?
Once all the hydrogen fuel is used up , stars go dark , planets go cold , life is over.
Still , as "SelfishGene" pointed out , the actual subatomic particles themselves may decay and fall apart - the universe may revert to the primordial soup that it was before the Big Bang.
And another Big Bang may take place , and all this , is , just a breath in a greater cycle of an undying cosmic heart.